Breech operating mechanism



1954 c. w. COCHRAN, JR

BREECH OPERATING MECHANISM Filed Dec. 5, 1951 INVENTOR ATTORNEYS a M a H F m m n. a I mfla 1 9 R 43" w m W n a v 5 t :2? a I: 2 fl w Patented Jan. 19, 1954 BREECH OPERATING MECHANISM the Navy Application December 5, 1951 SeriaiNo. 259,99

' 4 Claims. (01. 89*24) The invention relates to im rovements in breech mechanism for guns and more particularly to improved toggle spring breech Operating mechanism for a gun equipped with a reciprocable breechblock.

An important object of the invention is to provide breech operating mechanism with means for assisting in the opening and closing of a reciprocable breechbloc'k.

Another object of the invention is the provision of means oppositely biasing a reciproc'able breechblock in its open and closed positions.

A further object is to provide toggle spring linkage oppositely biasing a reciprocable breechblock in its open and closed positions.

Other objects and advantages of the invention will become apparent during the course of the following detailed description, taken in connection with the accompanying drawing forming a part of this specification, and in which drawing:

Figs. 1 and 2 are central vertical longitudinal sectional views of the breech end of a gun and showing the reciprocable breechblock and its associated operating mechanism in closed and open positions, respectively. 7

In the drawing whichfor the purpose of illustration shows only a preferred embodiment of the invention and wherein similar reference characters denote corresponding parts throughout the views, the numeral It! generally designates the breech end of a gun including a barrel portion A l l and a housing l2. Vertically s'lidably mounted in an upwardly and forwardly inclined g'uideway I3 for reciprocation between open and closed positions is a breechblock M which, in moving upwardly, becomes wedged against the base of a cartridge I5 in the gunbore I B.

Journaled transversely of the breech end of the gun and forwardly of the breechblock in its open position is a breech operating crankshaft I"! provided with a crank is for angular adjustment. Connected between the crankshaft I l and breechblock 14 is toggle joint mechanism 19 adapted to translate angular oscillatory motion of the crankshaft into rectilinear reciprocatory motion of the breechblock between its open and closed positions. This toggle joint mechanism [9 includes a lever arm 20 fixed on the crankshaft and having its free end pivoted at 2| to one end of a link 22 whose opposite end is pivoted at 23 2 extended dead-center position to a slightly buckled position in which the 'breechblock is closed, this toggle jeint movementbeing imparted by clockwise rotatieii of the crankshaft as viewed in Figs. 1 and 2. By rotating the crankshaft i? in a counterclockwise direction, the toggle joint is mcvee through its dead cen'ter position into a collaps'ed position wherein the breec'hblock I l is opened.

Connected between the crankshaft I1 and a pivot 25 mounted thereabove iii the breech end or the gun is toggle spring linkage 21 biased for collapsing movement res n a straightened positioii toward either brie of the two buckled positions shown inFigs; 1 and 2, wherein the breechblock I l is respectively bldsd and open. This toggle spring linkage it includes a lever arm is hired on the crankshaft and having its free end piyeted at 29 to the rod end of a telescopic link 36 including relatively aifi'all-y movable cylinder and rod portions 31,- 32; the cylinder end portion '31 bei-ii-g pivtd t6 the gun breech at 25.

Enciil-ing the iod 'pitioh 32 Within the (minder arid bearing against a flange 33 on the rod is all expenses 'c'dil spring 34 adapted to urge the cylinder and rod portions into axially eritended relation for lengthening thelink. The eeifibined lengths of t e lever arm 28 and the tlspi link 36 anally extended iS greater than the distaiie between the pivot 26 and crankshaft i'ljvherebyth spring as urges the toggle linkage 2'! from its straightened position toward either one at its me buckled positions.

In the ep'eration 6f the mechanism, as the breeelibloek it is opened, the lever arms 2c, 28 swing until the toggle spring linkage 2? passes over its dad cen-tei" pes'itio'ri whereupon the spring 36 assists iii opening the breechblock completely and then biases it in the open position. Also,-

the sweetener; is being closed, the toggle "g M e'fierates in a similar manner to clese thebreehbleck and bias it in its closed position.

Various changes may be made in the form of invention herein shown and described without departing from the spirit of the invention or the scope of the following claims.

What is claimed is:

1. In a gun provided with a breechblock reciprocably slidable between closed and open positions, a breechblock operating crankshaft jour= naled in the breech end of the gun, a toggle joint connecting said crankshaft and breechblock for translating oscillatory crankshaft motion into reciprocatory breechblock motion between positions wherein said breechblock is opened and closed respectively, and toggle spring linkage connecting said crankshaft and the breech end of the gun and biased for collapsing movement from a straightened position toward either one of two buckled positions, said breechblock being respectively open and closed when said toggle sprin linkage is in one or the other of said buckled. positions.

2. In a gun provided with a breechblock reciprocably slidable between closed and open positions, a breechblock operating crankshaft journaled in the breech end of the gun, a toggle joint connecting said crankshaft and breechblock for translating oscillatory crankshaft motion into reciprocatory breechblock motion between positions wherein said breechblock is opened and closed respectively, an abutment positioned for engagement by said toggle joint upon closing of said oreechblock, and toggle spring linkage connecting said crankshaft and the breech end of the gun and biased for collapsing movement from a straightened position toward either one of two buckled positions, said breechblock being respectively open and closed when said toggle spring linkage is in one or the other of said buckled positions.

3. In a gun provided with a breechblock reciprocably slidable between closed and open positions, a breechblock operating crankshaft journaled in the breech end ofthe gun, a toggle joint translating oscillatory crankshaft movement into reciprocatory breechblock movement between positions wherein said breechblock is opened and closed respectively, said toggle joint including a lever arm fixed on said crankshaft for swinging movement of its free end portion, and a link pivoted at one end to the swinging end portion of said lever arm and at its opposite end to the breechblock, said toggle joint being adapted to collapse upon movement of said breechblock into its open position through rotation of said crankshaft in one direction, said toggle joint being swingable, through rotation of said crankshaft in an opposite direction, past a straightened position to a slightly buckled position wherein said breechblock is closed, and toggle spring linkage biased for collapsing movement from a straightened position toward either one of two buckled positions, said toggle spring linkage including a lever arm fixed on said crankshaft for swinging movement of its free end portion, a link including relatively axially movable cylinder and rod portions one of said link portions being pivotally connected to the swinging end of the lever arm of said toggle spring linkage, pivot means connecting the other of said link portions to the breech end of the gun, and an expansion coil spring encircling said rod portion within said cylinder and adapted to urge the cylinder and rod portions of said link lengthening said link, the lengths of the lever arm and link of said toggle spring linkage in said into axially extended relation for axially extended relation being greater than the distance between said pivot means and said crankshaft whereby said spring urges said toggle spring linkage into one of said two buckled positions at opposite sides of its straightened position, said breechblock being respectively open and closed when said toggle spring linkage is in one or the other of said buckled positions.

4. In a gun provided with a breechblock reciprocably slidable between closed and open positions, a breechblock operating crankshaft journaled in the breech end of the gun, a toggle joint translating oscillatory crankshaft movement into reciprocatory breechblock movement between positions wherein said breechblock is opened and closed respectively, said toggle joint including a lever arm fixed on said crankshaft for swinging movement of its free end portion, an abutment positioned on said toggle joint for engagement upon closing of said breechblock, and a link pivoted at one end to the swinging end portion of said lever arm and at its opposite end to the breechblock, said toggle joint being collapsible upon movement of said breechblock into its open position through rotation of said crankshaft in one direction, said toggle joint being swingable through rotation of said crankshaft in an opposite direction, past a straightened position to a slightly buckled position predetermined bysaid abutment when the breechblock is closed, and toggle spring linkage biased for collapsing movement from a straightened position toward either one of two buckled positions, said toggle spring linkage including a lever arm fixed on said crankshaft for swinging movement of its free end portion, a link including relatively axially movable cylinder and rod portions, one of said link portions being pivotally connected to the swinging end of the lever arm of said toggle spring linkage, pivot means connecting the other of said link portions to the breech end of the gun, and an expansion coil spring encircling said rod portion within said cylinder to urge the cylinder and rod portions of said link into axially extended relation for lengthening said link, the lengths of the lever arm and link of said toggle spring linkage in said axially extending relation being greater than the distance between said pivot means and said crankshaft whereby said spring urges said toggle spring linkage into one of said two buckled CHARLES WILLIAM COCHRAN, JR.

References Cited in the file of this patent UNITED STATES PATENTS Name Date Lehmann Apr. 4, 1911 Number 

